Certificate of correction



Patented Sept. 15, 1931 UNITED STATES PATENT OFFICE STEPHAN JUST, 0F BASEL, SWITZERLAND, ASSIGNOR TO THE FIRM.FABBEREI- & OPPRETUR GESELLSCHAFT (VORMALS A. BLAVEL & FRITZ LIN'DENMEYER), 0F

BA SEL, SWITZERLAND TREATMENT OF SILK A problem of great interest in the silk industry is the durability of weighted silk. The protective treatments hitherto known have been based on-the action of reducing substances. such as thiosulphates, formaldehyde bisulphite, hydroxylamine, hydroquinone or thin-urea. These treatments require operation in acid solutions. On the other hand it has been proposed to protect weighted silk by a subsequent treatment with an annnonia-formaldehyde preparation or rhodan compounds, but it has been observed in this case that these compounds produce undesirable color modifications or spots- Further it is well known that after acid metal salt solutions an alkaline treat ment is used with alkali phosphate or car bonate which belongs to the wei hting proper process and serves only to x the mordant salt and does not concern the final reaction after dyeing. By the present invention, however, a moderately long treat ment of the silk after complete weighting and in the course of subsequent dyeing, printing and finishing operations in an additional alkaline bath free from formaldehyde and rhodan, such as a solution of ammonia, of a phosphate (trisodium phosphate), of a borate, of an organic base and so on, produces very good protective effects in respect of rotting under the influence of both light and temperature without affecting the color or other properties of the silk. The fundamental novelty of the invention is derived from the observation that weighted silk fibre when in a neutral or feebly alkaline condition exhibits far greater resistance to the chemical processes which occur during storage than if there is present even a trace of acid. Researches, made by the inventor, show that best results are obtained when the concentration of H-ions. determined in an aqueous extract of the fiber, ranges between min. pH 7.0 and max. pH 10. (Temperature of determination 20 C.).

The effect of the invention is surprising For example, the. tensile strength of the weft of'a normal dyed weft-silk. tied with the sarsenet ribbon, after 4 months storage in a tropical climate in a place protected in Germany November 8, 1924.

from direct solar radiation. diminished from 20,7 kilos to 10,4 kilos, whereas the silk which had been treated by this invention diminished in tensile strength only to'an insignificant amount, namely from 19.6 kilos to 10,1. These figures show the technical advance made by the invention without further demonstration. There is no effect on the lustre of the fibre and the effect on the feel of the material is such that it cannot be regarded as technically disadvantageous but rather as an improvement for certain purposes.

The invention canbe applied to silk in hanks or piece goods, or in mixed fabrics, after the weighting operation is finished, during or after the dyeing, printing and finishing. The essential being that the additional alkaline bath is capable of rendering the fiber free from acid substances by producing min. pH 7.0 to max. pH 10, determined in an aqueous extract of the fiber at 20 C.

The following examples illustrate the invention:

Ezvample 1 Ezrample 2 The. silk receives after the operation of weighting it with water glass, as usual, two soap baths at C.. there being added to the second bath in dyeing operation 5 grams of trisodium-phosphate per litre of the liquor, and in some cases. particularly for light tints. the necessary dyestufi's for the dyeing. whilst for darker shades the dyestuffs may be added in a following hath. A subsequent treatment with acid is not pernnssible.

lOO

Example 3 The weighted and dyed silk in hank or web is treated in the usual manner with a. dressing solution consisting of an alkaline solution of tragacanth in combination with BIl31pl1th lamine as a feeble base; only a. feeb y al aline reaction of the fibre is produced.

What I cleim is:

1. A method for increasing the permw nence and stability of completely weighted and dyed silk fibre consisting in treating the fibre with a basic bath free from formaldehyde compounds, after the weighting, to neutralize any remaining acidity of the fibre.

2. A method for increasing the permanence and stability of completely weighted and dyed silk fibre consisting in treating the same with a bath which contains an in organic base and which is free from formaldehyde compounds, after the weighting, to neutralize any remaining acidity of the fibre.

3 A method for increasing the permanence and stability of completely weighted and dyed silk fibre consisting in treating the same with a. bath which contains ammonia, but is free from formaldehye compounds, after the weighting.

4. A method for increasing the permunence and stability of completely Weighted and dyed silk fibre consisting in treating the same with a bath which contains inorganic alkaline salts, but is free from for nmldehyde compounds, after the weighting.

5. A method for increasing the permunence and stability of completely weighted and dyed silk fibre consisting in treating the same with a bath which contains disodium phosphate but is free from formaldehyde compounds, after the weighting.

In witness whereof I have hereunto signed my name this 3rd day of January STEPHAN JOST.

Example 8 The weighted and dyed silk in bank or web is treated in the usual manner with a dressing solution consisting of an alkaline solution oftragacanth in combination with fl-na hth lamine as a feeblebase; onl'y a. feebiy al aline reaction of the fibre is produced.

What I claim is:

1. A method for increasing the permanence and stability of completely weighted and dyed silk fibre consisting in treating the fibre with a basic bath free from formaldehyde compounds. after the weighting, to neutralize any remaining acidity of the fibre.

2. A method for increasing the permancnce and stability of completely weighted and dyed silk fibre consisting in treating the same with a bath which contains an inorganic base and which is free from formaldehyde compounds, after the weighting,

to neutralize any remaining acidity of the fibre.

3. A method for increasing the permamemos and stability of completely weighted and dyed silk fibre consisting 1n treating the same with a bath which contains ammonia, but is free from formaldehye compounds, after the weighting.

4. A method for increasing the permanence and stability of completely weighted and dyed silk fibre consisting in treating the same with a bath which contains inorganic alkaline salts, but is free from formaldehyde compounds, after the weighting.

5. A method for increasing the permanence and stability of completely weighted and dyed silk fibre consisting 1n treating the same with a bath which contains disodium phosphate but is free from formaldehyde compounds, after the weighting.

In witness whereof I have hereunto signed my name this3rd day of January STEPHAN J 0ST.

CERTIFICATE OF CORRECTION.

Patent No. I, 823, 606.

STEPHAN JOST.

GrantedSeptember 15, 1931, td

It is hereby certified that the name of the assignee in the above numbered patent was erroneously written and printed as to the firm "Farberei- & Oppretur Gesellschaft (Vormals A. Blavel 8: Fritz Lindenmeyer), of Basel, Switzerland" whereas said name should have been written and printed as to the finn F'drberei- & hppretur 'Gesellschaft (Vormals A. Clavel 8: Fritz Lindenmeyer), of Basel Switzerland, as shown by the records of assignments in this office; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 17th day of November, A. D. 1931.

CERTIFICATE OF CORRECTION.

Patent No. 1,823,606. Granted September 15, 193i, to

STEPHAN JOST.

It is hereby certified that the name of the assignee in the above numbered patent was erroneously written and printed as to the firm "Farberei- & Oppretur Gesellschaft (Vormals A. Blavel & Fritz Lindenmeyer), of Basel, Switzerland" Whereas said name should have been written and printed as to the firm F'drberei- & Appretur Gesel'lschaft (Vormals A. Clavel 8r Fritz Lindenmeyer), of Basel, Switzerland, as shown by the records of assignments in this office; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 17th day of November, A. D. 1931. 

